Advances in endoscopic imaging in ulcerative colitis

Abstract

Modern strategies for the treatment of ulcerative colitis require more accurate tools for gastrointestinal imaging to better assess mucosal disease activity and long-term prognostic clinical outcomes. Recent advances in gastrointestinal luminal endoscopy are radically changing the role of endoscopy in every-day clinical practice and research trials. Advanced endoscopic imaging techniques including high-definition endoscopes, optical magnification endoscopy, and various chromoendoscopy techniques have remarkably improved endoscopic assessment of ulcerative colitis. More recently, optical biopsy techniques with either endocytoscopy or confocal laser endomicroscopy have shown great potential in predicting several histological changes in real time during ongoing endoscopy. Here, we review current applications of advanced endoscopic imaging techniques in ulcerative colitis and present the most promising upcoming headways in this field.

Keywords:

• advanced endoscopic imaging
• chromoendoscopy
• colitis-associated cancer
• colonoscopy
• ulcerative colitis

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• When performing surveillance colonoscopy, high-definition imaging is suggested in place of standard definition.

• When performing surveillance colonoscopy, dye-based chromoendoscopy using either indigo carmine or methylene blue with targeted biopsies of any suspicious area should replace the conventional protocol based on four-quadrant random biopsies every 10 cm.

• High-magnification combined with dye-based chromoendoscopy can improve the differentiation of neoplastic from non-neoplastic lesions in ulcerative colitis (UC).

• High-magnification combined with dye-based chromoendoscopy can refine disease severity assessment in subject with mild or apparently quiescent UC, thereby predicting the corresponding histopathological degree of inflammation.

• Dye-less chromoendoscopy with Narrow Band Imaging and i-scan can better detect subtle mucosal inflammatory changes in patients with mild or apparently quiescent UC, thereby refining the assessment of mucosal healing and predicting the corresponding histopathological degree of inflammation.

• In vivo optical biopsy with endocytoscopy can characterize in real time either superficial histological architectural features or subcellular details, and predicts the corresponding histopathological degree of inflammation with high accuracy in inflammatory bowel disease.

• In vivo optical biopsy with confocal laser endomicroscopy allows the differentiation in real time of neoplastic from non-neoplastic lesions with high accuracy in long-standing UC.

• In vivo optical biopsy with confocal laser endomicroscopy enables the assessment in real time of several superficial histological architectural features or cellular details, and can predict the corresponding histopathological degree of inflammation, the differential diagnosis, the presence of intestinal barrier impairment and long-term clinical outcomes.

• Molecular imaging may assess specific biochemical processes upon the mucosal intestinal surface with extremely promising applications in basic science, surveillance colonoscopy, and as a biomarker of disease activity or response to treatment.